# -*- coding:UTF-8 -*-
"""
@Project :每日一题
@File :乘积尾零.py
@IDE :PyCharm
@Author :Kinght_123
@Date :2022/1/23 14:12
"""
if __name__ == '__main__':
res = 0
ls = []
s = 1
with open('nums.txt') as fp:
for line in fp.readlines():
ls.append(list(line.strip().split(' ')))
for i in range(len(ls)):
for j in range(len(ls[0])):
s *= int(ls[i][j])
while not s % 10:
s //= 10
res += 1
print(res)